UPS --->> inverter

[vermiman]

Has anyone here used a UPS as an inverter? I've seen a few videos on youtube about it. Is it really possible? I already have a UPS that has a bad battery. I am trying to cut corners from wherever I can.

[Sunking]

It can be done, but UPS are designed for very short term operation. They are made to supplu power from batteries for a few minutes until generators start up and take over. Limiting factor is the batery

[vermiman]

It can be done, but UPS are designed for very short term operation. They are made to supplu power from batteries for a few minutes until generators start up and take over. Limiting factor is the batery

I'm talking about hooking it up to a longer lasting deep cycle battery.

[Sunking]

I'm talking about hooking it up to a longer lasting deep cycle battery.

Yes I know. But unless you are getting a salvaged UPS for free or cheap as dirt,and know how to modify it, not sure what the point is as buying a new one is very expensive and not designed to do what you want.

Basically a off-grid solar system is a UPS.

There are 4 basic kind of UPS out there. Do you even know what kind you are looking for?

[vermiman]

I was given a UPS several months ago that has a bad battery. No, I don't know about the different types of UPS. I thought that they basically keep a small battery charged and then in the event of a power failure they invert the DC power in that battery and allow you a short time to shut down your computer. I was thinking with a higher capacity battery hooked up to it, that it would give similar capabilities as an inverter. I was not intending on buying a UPS and converting it. If that was the case then I'd just go out and purchase an inverter. I'm just trying to cut any corner that I can on my first DIY panel project.

[Mike90250]

Many UPS's output only a mod square wave, not a sine wave. They also have MINIMAL heat sinking, because they expect the battery to run down in just a couple minutes.

[Sunking]

The only UPS system that can be used for this application is a true industrial dual conversion AC - DC - Ac inverter. They are very expensive.

They take the AC input from th commercial source, rectify it t keep the batteries fully charge, plus enough capacity to fully power the Inverter fed equipment. The are always on line. The batteries are designed to only last a few minutes, just enough for the generators to start up and take over. The inverter section will work, but all the rectifiers, charge controllers, and batteries have to be ripped out and replaced in a big way.

The panels have to collect enough energy to power everything for at least 24 hours if not more, and the batteries 5 days or more. That is not an easy mod or cheap.

[vermiman]

Well then, it looks like this would be a bad idea. I guess for awhile I could try to use items that can run DC without an inverter. Thank you all for your help.

[MarineLiner]

I'm talking about hooking it up to a longer lasting deep cycle battery.

[mogollonrim]

Larger capacity batteries will work well to keep the UPS up longer, just match the voltage of the original batteries and watch the heat generation. Compared to an inverter a UPS will not be as efficient. Like Mike90250 said about the modified sine wave. They convert more of the input power to heat than an inverter.

[MarineLiner]

Larger capacity batteries will work well to keep the UPS up longer, just match the voltage of the original batteries and watch the heat generation.

With the max amps as in the spec.

Compared to an inverter a UPS will not be as efficient.
Like Mike90250 said about the modified sine wave.
They convert more of the input power to heat than an inverter.

But still can be use upto it's max amps.
Inverter is the 3rd of an UPS parts.
1st. Controller.
2nd. Battery.

[Mike90250]

Many ups's only have a small heat sink for the inverter, since the batteries only last a few minutes. If you plan on full time use, you may have to add cooling for the inverter section.